Spatial and temporal distribution of mallard band recoveries in North America

Waterfowl harvest and population monitoring in North America has resulted in large amounts of longitudinal release and encounter data. This data has shown that the Mississippi flyway is studded with hotspots of migrating waterfowl, most notably the Prairie Pothole Region (PPR) and the Mississippi Alluvial Valley (MAV). Past studies have analyzed variability in the release and harvest of waterfowl but have not included age and sex specific differences in the distribution of band recoveries. Shifting hunting demographics, conversion of habitat to agriculture, and fluctuating patterns of climate change all contribute to variability in band recoveries from mallards (Anas platyrhynchos). We analyzed spatial and temporal variability in mallard band recoveries to reveal areas with potentially outsized influence on waterfowl management and conservation. We identified the spatial distribution of band recoveries from mallards banded in the PPR using kernel density estimator analyses. The distribution of mallard harvests showed strong temporal variability, with yearly shifts in band recovery hotspots. Results also showed substantial spatial variability, with some regions exhibiting higher recovery and reporting rates than others. In particular, the MAV had some of the highest densities of band recoveries. We predict that fluctuations could result from many variables, including spatially variable band reporting rates and temporal shifts in environmental and social pressures.  ​